Handsome silver spoon Texan Trevor Forrest can't always control his tendencies to flirt and gamble, even on honeymoon cruise to Tahiti with Lindsey Ross Forrest, which may compromise their business ambitions. The ship captain asks FBI agent Gwen Merced, on cruise, to investigate discretely when Trevor goes missing, probably fallen or pushed overboard as blood traces are found. It's unclear whether the Hungarian business trio Luka, Max and Ben are innocent flirtatious gamblers like Trevor or criminals, but others have hidden agendas too.
When mankind beams a radio signal into space, a reply comes from ‘Planet G’, in the form of several alien crafts that splash down in the waters off Hawaii. Lieutenant Alex Hopper is a weapons officer assigned to the USS John Paul Jones, part of an international naval coalition which becomes the world's last hope for survival as they engage the hostile alien force of unimaginable strength. While taking on the invaders, Hopper must also try to live up to the potential that his brother, and his fiancée's father—an Admiral—expect of him.
Steve McGarrett returns home to Oahu, in order to find his father's killer. The governor offers him the chance to run his own task force (Five-0). Steve's team is joined by Chin Ho Kelly, Danny "Danno" Williams, and Kono Kalakaua.